In monitoring or detecting changes of fluid pressure, or surges of fluid, within a pipe, or conduit, it has been and is the practice to cut into the pipe and insert an "in line" transducer within the pipe. In the prior art, such transducers have included quartz crystal type transducers, strain gage type transducers and vane type (mechanical type) transducers. All of the foregoing transducers have been less than completely satisfactory because they have to be inserted into the pipe, or conduit, which in itself creates problems. Once inserted in the pipe, such transducers are subject to the adverse effects of the fluid per se, chemical reactions therewith, dirt found therein and large direct changes of pressure therefrom. Under such continual adverse situations, the foregoing transducers have often failed. In one application, namely the monitoring of diesel fuel injections into a diesel engine, for the purpose of "timing" or "tuning" or adjusting a diesel engine, the use of the "in-line" transducer is generally employed and it gives rise to problems. In diesel engine operation, a pump is employed to pump fuel, or inject fuel, into each chamber of the engine wherein there is a piston moving up and down to compress the fuel and simultaneously increase its temperature until it (the fuel) explodes or "fires." The time during the piston stroke at which the fuel is injected is somewhat critical for efficient operation. The fuel is pumped by the pump to each chamber in some form of serial mode depending on the number of cylinders or chambers in the engine. Accordingly each of the pipes from the pump to the chambers is of equal length so that the fuel injected into chamber number one is injected at a time relative to the position of the piston in chamber number one, which is the same as the time of the fuel injection into chamber number two relative to the position of the piston in chamber number two and so on for each of the chambers and its associated piston.
It becomes apparent then that if a fuel line from the pump to a chamber is cut and separated so that an "in line" transducer can be added then the time for the fuel to leave the pump and pass into the chamber (connected to the increased fuel line) is increased. The increased fuel line changes the "timing" for its associated chamber and this is highly undesirable.
Accordingly it is the practice to cut away part of the fuel line into which the "in line" transducer is inserted, by an amount equal to the length of the "in line" transducer so that when the transducer is added to the shortened fuel line, the overall length is the same as the length of each of the fuel lines to the pump which have not been shortened. The present transducer arrangement eliminates the need for an "in line" transducer which, of course, eliminates the need for cutting into the fuel line, shortening the fuel line, and exposing the transducer to the adverse effects (mentioned earlier) of being immersed directly in a fluid flow having a varying pressure characteristic.